| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a period of [noun] | 575 |
|
| 2 | [prep] a period of [noun] | 575 |
|
| 3 | over a period of [noun] | 296 |
|
| 4 | over a period of [noun] | 296 |
|
| 5 | [verb] a period of [noun] | 139 |
|
| 6 | for a period of [noun] | 59 |
|
| 7 | for a period of [noun] | 59 |
|
| 8 | after a period of [noun] | 57 |
|
| 9 | after a period of [noun] | 57 |
|
| 10 | be a period of [noun] | 52 |
|
| 11 | [be] a period of [noun] | 52 |
|
| 12 | [adv] a period of [noun] | 47 |
|
| 13 | in a period of [noun] | 38 |
|
| 14 | in a period of [noun] | 38 |
|
| 15 | [conj] a period of [noun] | 32 |
|
| 16 | [v-ing] a period of [noun] | 29 |
|
| 17 | [adv prt] a period of [noun] | 27 |
|
| 18 | [vb past] a period of [noun] | 27 |
|
| 19 | over a period of [noun] | 25 |
|
| 20 | over a period of [noun] | 25 |
|
| 21 | [was/were] a period of [noun] | 20 |
|
| 22 | was a period of [noun] | 20 |
|
| 23 | [vb base] a period of [noun] | 20 |
|
| 24 | follow a period of [noun] | 19 |
|
| 25 | during a period of [noun] | 19 |
|
| 26 | during a period of [noun] | 19 |
|
| 27 | [to-vb] a period of [noun] | 17 |
|
| 28 | [subord] a period of [noun] | 17 |
|
| 29 | to a period of [noun] | 16 |
|
| 30 | to a period of [noun] | 16 |
|
